CVE-2026-69212 — Http4s: FollowRedirect middleware leaks credentials over https->http same-authority redirect
Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, The FollowRedirect client middleware strips Authorization and Cookie headers only when a redirect …
Published: 2026-09-15 · CVSS: 5.9 · CVSS 3.1
Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, The FollowRedirect client middleware strips Authorization and Cookie headers only when a redirect changes authority, but authority comparison excludes the URI scheme. A same-authority redirect from HTTPS to HTTP therefore preserves credentials and transmits them over a plaintext connection. An attacker who can induce the downgrade and observe the network can capture those sensitive headers from applications using FollowRedirect. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7